DE 10 2008 020 954 A1 describes such a camera arrangement. Camera arrangements having a camera looking through a vehicle windshield are used for lane detection, traffic sign recognition, and the like. In modern vehicles, the windshield (i.e., a vehicle window pane) is positioned at a relatively shallow angle (e.g., between 20° and 25°) with respect to the horizon for aerodynamic and aesthetic reasons. This can cause a light beam incident in a horizontal direction to be strongly refracted upon entering the windshield from the vehicle exterior and to again be strongly refracted upon exiting the windshield into the vehicle interior. A light beam guide such as a prism-type light conductor can be coupled without refraction, or with only an insignificant amount of refraction, to the inner side of the windshield so that the beam path is modified advantageously. Such light beam guides can nevertheless give rise to geometrical distortions and disturbing color defects.
Such geometrical distortions include compressive deformations or elongations as well as warping of the camera image. They are relatively unproblematic as they can be removed computationally after the fact. On the other hand, compensation for color errors in prism arrangements can be relatively tedious. In many cases, the prism arrangement includes multiple prisms, which are made of different and sometimes expensive materials or which are to be arranged in geometrically complex ways with respect to one another.